This invention relates to the sector of manual trigger-dispensing devices for liquids, for example for the hygiene of the home, the deodorisation of rooms, the treatment of fabrics before ironing, and the like. In particular, this invention relates to a dispensing head for a trigger dispensing device provided with a spring for the return of the trigger.
Trigger dispensing devices are very widespread, as can be seen on supermarket shelves, especially for their ease of use and functionality. Every year many hundreds of millions of pieces are produced.
Therefore, it is understandable that even a slight improvement in the production process or a slight change of the components, such as to allow for example a structural simplification or a saving of raw material, can actually have a significant impact on the profitability of production.
One of the essential components for such trigger dispensing devices is the return spring which, after the actuation of the trigger, returns it to its initial rest position.
The return spring is a critical component of the dispensing device. For example, it is repeatedly stressed during the life of the dispensing device, for which it must be sufficiently robust to prevent any breakages or made of suitable materials, which are often expensive. For example, acetal resin, such as POM (Polyoxymethylene) is often used.
Furthermore, during assembly of the dispensing head, the application of the trigger to the frame and the return spring between the trigger and frame, is always a critical step and has to be carried out at a reduced speed, often not satisfactory compared to those attainable in other production steps.